September Update patch notes, courtesy of mechberg on the official forums:

September Release Notes

The September Update for Forza Motorsport 7 is here and introduces new features like the first version of our “Experimental Drag” and our new “Meetups” feature, among others. See our full September Announce story on the Web site for more detail. In addition to those features, this update introduces important fixes and improvements to the game including:

GENERAL

Fixed an issue where players who used a “Back to the Front” mod card while using a rolling start on Spa would result in that player starting in front of a tire wall.

Fixed an issue where, when setting the Game Type to Drift in Free Play and setting the end condition to “laps” would cause the Drift points UI elements to disappear.

Fixed an issue where, when competing in a race that compares Best Lap scores, the Distance Ahead HUD does not clearly indicate which laps are dirty laps.

Shortened the length of the post-race top header bar so that it does not obscure the player’s helmet.

Fixed an issue where, in the pre-race menu Test Drive, if the user has previously set Drivatars to 2 or more, drift smoke would not appear when the user is driving.

Fixed an issue where framerate would significantly drop after quickly scrolling through the Buy Cars menu for an extended period of time.

Players can now tint the “Carbon Fiber Polished” special color.

Fixed the angle and zoom level with the mini-map in Drag races.

SPECTATE

Fixed an issue where the G-Force numerical value would sometimes not appear in the Player Info panel during Spectate.

Fixed an issue where players who are still racing at the end of a race have their “Race End” information displayed as distance from the race leader instead of distance from the finish line.

Fixed an issue where best Drift score was not populating in the Race Stats Spectate telemetry.

Fixed an issue where, when spectating a Drift event, the Player Focus screen stats would not update if the spectator entered the event after it had begun.

Fixed an issue in multiclass Spectate where the Bucket Line on the Player Info telemetry would show the incorrect color if Bucket 1 had zero cars in it.

Fixed an issue where, when spectating a drift race with two teams and scoring type set to individual, spectators would see players as “red” instead of seeing each player with their correct team color.

Fixed an issue in multiclass Spectate races where distance gap data for the slower car class calculates the figure from the overall race leader.

Fixed an issue in multiclass Spectate races where, if a driver has scored points on a previous lap, their card would briefly show a “+0” added to their score each time the lap points data refreshed.

Fixed an issue where “Best Lap” data would not update on the Race Stats panel.

Fixed an issue where, if a quits to the lobby and then enters Spectate again, grid changes are not reflected in the ticker. This fix also applies to Time Intervals data in Spectate where players leave and go back into Spectate the same race.

Fixed an issue where top speed telemetry data does not update, even after a new lap record is set.

Fixed an issue where in multi-class Spectate, where leader and top speed telemetry don’t update when there are zero cars in Group 1 (Red).

When voting on tracks in MP lobbies, players will now see the percentage of total vote each track option has.

Disabled the “ready” button in MP lobbies when game has auto-readied players for the next race.

Fixed an issue where players who have spectate enabled in a lobby could change their driver group, resulting in them not having a car selected, and causing long loading times for other players in the lobby.

Fixed an issue where, when a player in a party would quit out of a race towards the end of the race launch countdown clock, and would have to wait for other party members to accept, that player would be booted to the main menu.